Set up the following query in ApiSandbox:
- titles=<<the name of a page that contains multiple wikilinks>>
Note that rvlimit=10 gets pre-filled for you. Execute the request, and you get a somewhat cryptic error (rvmultpages), telling you not to set rvlimit when using a generator.
To get the request to work, you have to clear rvlimit manually. This is particularly annoying when you are adding and removing query modules, as rvlimit gets set back to 10 every time.
Going by what the error message says, this issue may also occur when querying multiple pages via "titles" or "pageids".